Governor for elevator safety devices



Nov. 11, 1941. v MCCORMICK 2,262,366

GOVERNOR FOR ELEVATOR SAFETY DEVICES Filed Jul 25, 1939 2 Sheds-Sheet 1 WITNESSES:

' ATT EY Nov. '11, 1941.

H. V. McCORMlCK GOVERNOR FOR ELEVATOR SAFETY D EVICES I WITNESSES: 2 6037M Patented Nov. 11, 1941 GOVERNOR FOR ELEVATOR DEVICES SAFETY Harld v. McCormick, Westfield, J.,a ssignor to ,Westinghouse Electric Elevator Company,

Jersey City, N. J., a corporation of Illinois Application July 25, 1939, Serial No. 286,342

4 Claims.

My invention relates to governors for elevator safety devices.

One object of the inventionis to provide a safety governor which shall be light in weight,

accurate in operation, and simple andinexpensive to construct, install, and maintain in operation. r

Another object is to provide a governor which shall be practically noiseless when it is started or stopped by the starting and stopping of the elevator car with whichit is associated.

A further object is to provide a safety system in which the governor will causethe safety jaws to clamp the guide rails promptly when the car exceeds its predetermined safe speed and,

in which onlya small movement of the governor parts is necessary to effect a grippingaction on the governor cable when the governor is actuated by an excessive speed of the car.

For a better understanding of the invention, reference may be had to the. accompanying drawings in which:

Figure 1 is a view in side elevation of ernor embodying my invention;

Fig. 2 is a top plan view of the governor illustrated in Figure 1; and

Fig. 3 is a view in front elevation of the governor illustratedin Figure 1.

Referring more particularly to the drawings, I have illustrated a governor comprising a frame 10, a governor sheave II supported in the frame for operation by a safety cable l2, a jaw member l3, and a notched disc or ratchet wheel 14 and pair of centrifugal arms or fly weights l5 and I6 for operating the jaw member to grip the cable when the governor sheave exceeds a predetermined safe speed.

The frame l0 comprises a pair of heavy metal side plates 18 and I9 maintained in position by a plurality of connecting rods or bolts 20 and spacers 2| mounted in position to hold the plates a desired distance apart. The side plate I8 is partly broken away by the line I8a in Fig. 1 to permit clearer illustration of thesheave and other parts. The frame is illustrated as anchored on a concrete base 23 by a plurality of expansion a govbolts 24 which pass through the lower spacing bolts 20. A sheet metal cover 25 is disposed over the top and front sides of the frame and is held in position by a plurality of machine screws 26.

The governor sheave II is provided with a U- shaped groove in its outer peripheryto receive the safety governor rope or cable l2 and it is mounted in the frame by means of an axle'or shaft 28, the outer ends of which are secured in the plates by suitable nuts 29 and washers 30. A plurality of spacing sleeves 3|, 32, and 33 are mounted on the shaft 281to maintain the sheave in its correct position. The sheave may be supported on the shaft 28 bya bronze bushing (not shown) which may be provided with a fitting 35 mounted in a shoulder 36'for grease gun lubrication. i

From the foregoing, it will be. obvious that, with the safety cable [2 disposed in the groove Ila in the outer periphery of the sheave II, the sheave will rotate in accordance with the speed of the car (not shown) to which the rope is attached as disclosed in the James Dunlop Patent No. 1,937,035, issued November 28, 1933, and assigned to the Westinghouse Electric Elevator Company, to which reference may be had for further details as to the operation of safety cables.

The jaw member I3 may be constructed as an irregularly shaped casting having a shoe section 40 on its central portion for engaging the safety cable and clamping it against the sheave. The one end of the jaw member is enlargedto provide a hinge portion 4| adapted to lie between a F pair of hinge blocks 42 and 43 and be hinged thereon by a pin 44. The blocks 42 and 43 are mounted on the side plate I9 and maintained in position thereon by a pair of nuts 45. The free end 46 of the jaw member I 3 is enlarged and provided with a circular recess 41 for the inner end of a compression spring 48 which is maintained inoperative position on a connector or rod 49 by a washer 50 and a nut 51. The rod 49 passes through an aperture 52 in the free end of the jaw member and is provided with a shoulder 53 which bears against the jaw member and limits the passage of the rod therethrough. It will be obvious that the shoulder 53 and nut 5| serve to hold the spring 48 in compression against the jaw member and that the amount of compression or load on the spring may be easily adjusted by rotating the nut 5|.

The shouldered end of the connecting rod 49 is pivotally connected by a crank pin 55 to the outer circular portion of the ratchet Wheel l4.

The ratchet wheel is provided with a plurality of ratchet teeth 51 and is rotatably mounted upon the shaft 28 at the side of and concentric with the sheave, its hub 58 being disposed between the sleeve spacers 32 and 33. The ratchet wheel is preferably cast with a counterweight section 68 which biases the wheel in clockwise direction in Figure 1, thereby maintaining the rod 49 with its shoulder 53 disposed against the free end 46 of the jaw member I3.

The safety jaw is provided with a downwardly extending arm 6| in which is a machine screw 62. The outer end of the screw is so located as to impinge against a stop member such as the bent-up portion 63 of a sheet metal partition 64 when the jaw member is moved outwardly away from the safety cable. The sheet metal partition may be attached to the side plates I8 and I9 in any suitable manner, as by welding or by small angle irons (not shown). The stop member 63 maybe bent by a pair of heavy pliers when the governor is installed, to the correct position to limit the outer movement of the jaw member to the desired distance. The opposing action of the weight on the wheel and the stop member against the jaw member cause the wheel and the jaw member to normally remain in inactive position.

Inasmuch as the weighted ratchet wheel biases the free end of the jaw member and the rope shoe 48 away from the governor sheave, it will be obvious that the jaw will be normally maintained in such position that its shoe 4!] will be out of engagement with the safety rope but will be very close thereto so that little movement will be required to move it into its rope clamping position.

The centrifugal arm I6 is provided with a weight section 65 and a bifurcated section having two arm portions 66 and 61. The weight 65 is mounted in an opening 98 in the web I of the sheave with the arms 66 and 61 astride the spoke 69. A bearing pin I9 passes through a bearing boss H on the spoke and through the bifurcated arm to provide a bearing for the arm so that it may move freely under the centrifugal force exerted upon it when the sheave is rotated by the safety rope. The weight portion 95 is thick enough to extend outward slightly beyond the sides of the sheave and it is also provided with a groove I3 to permit it to fly outwardly under centrifugal action a predetermined distance without hitting the inner periphery of the sheave. A fibrous washer or stop member I4 is secured to the web I5 in position to limit the inner movement of the centrifugal weight 65 and at the same time eliminate any noise that might be made by the weight striking against the metal web of the sheave. With this noise reducing stop member I4 in place, it will be found that the sheave will operate with very little noise in starting and stopping and that none of the usual clicking noise of governor sheaves will be apparent when the car stops and starts.

The centrifugal arm I5 is similar to the arm I6 in that it is provided with a weight portion I8 and a pair of bifurcated arms 79 and 80. It is mounted on the spoke M of the sheave by means of a pin 82 which permits the weight portion I8 to move in and out in accordance with the centrifugal force developed by the speed of rotation of the sheave. A counterweight bar 83 is connected by means of a pivot pin 84 to the centrifugal weight 18 and a pivot pin 85 to the arm 61 of the centrifugal weight I6 so that the weights will counterbalance each other and operate in unison.

In order to counterbalance the centrifugal force on the centrifugal weights and bias them inwardly, a rod 98 is pivotally connected by a pin 9| to the outer end of the arm 89 with its free end disposed in an aperture 92 in a projecting lug 93 on the spoke 94 of the governor sheave and a compression spring 95 is mounted on the rod between the lug 93 and the washer 96. An adjusting nut 91 is provided to hold the cap washer in any desired position so that the spring 95 may be compressed to apply the desired biasing force to the centrifugal weights I5 and I6. A pawl 99 on the outer end of the arm I9 of the centrifugal weight I5 is provided for catching in the next ratchet tooth 51 when the safety rope causes the sheave to exceed a predetermined speed.

A switch I99 is mounted upon the partition 64 in position to be opened by the jaw member when the governor operates to stop the car. The switch comprises an insulation block I8I which may be secured to the partition by a plurality of screws I92 and which has mounted in it a pair of contact strips I93. The contact strips are disposed to engage a conducting strip I94 mounted on a supporting bar I95, the upper end of which is secured to the arm BI by the machine screws 62. As illustrated in the drawings, the contact strip I94 and the contact members I83 are normally disposed in engagement with each other while the car is operating at a safe rate of speed. The contact members I83 may be connected in the control circuit for the car so that operation of the governor to stop the car will open the switch I99 and shut off the power to the car.

In the normal operation of the governor, the safety rope I Z-travels along the groove in the sheave II and causes the sheave to rotate in accordance with the speed of the car. The compression spring 95 is set between compression nut 91 to bias the centrifugal weights to the point where they will move outwardly beyond a predetermined point when the car exceeds a predetermined speed. It will be assumed now that the car exceeds its predetermined safe speed, thus causing the sheave to rotate so rapidly that the centrifugal force generated in the weights I5 and I6 causes them to move outwardly beyond a predetermined point. As the weights move outwardly beyond the predetermined point, the pawl 99 engages one of the teeth 51 in the ratchet wheel I4. The engagement of the pawl 99 with the wheel I4 causes it to be rotated with the sheave in counterclockwise motion (Fig. 1). The rotation of the wheel I4 exerts a pull on the rod 49 which in turn pulls the free end 46 of the jaw member I3 toward the sheave, thus causing the shoe 4!] to grip the governor cable to retard or stop its further movement. The degree of force which the shoe 49 applies to the governor cable against the governor sheave will be proportionate to the load stored in the compression spring 48 which may be adjusted to stop the cable instantly or permit it to slip slightly.

From the foregoing description, it will be apparent that I have provided a safety governor which will operate almost instantly when a car exceeds a predetermined safe speed, that the governor parts are simple andare so arranged so as to require a very slight movement to place them in effective operation, and that the mechanism is compact and simple to manufacture, install, and maintain in operation.

Although I have illustrated and described only one specific embodiment of my invention, it is to be understood that modifications thereof and changes therein may be made without departing from the spirit and scope of the invention.

I claim as my invention:

1. An elevator safety device governor comprising a frame, a shaft disposed in the frame, a sheave mounted on the shaft for rotationby a safety cable, a pair of fly weightsmounted on the sheave in position to be moved outwardly by centrifugal force when the sheave is rotated, means for biasing the weights toward their inner position, a ratchet wheel rotatably mounted on the shaft concentric with the shaft and the sheave and having a weighted portion for biasing it toward a predetermined position, a pawl disposed to be operated by the weights for engaging the ratchet wheel and rotating itwith the sheave when the sheave exceeds a predetermember away from the sheave to a predetermined distance, a rod having its one end conneoted to the wheel and its other end disposed through an aperture in the free end of the jaw member and having a shoulder to limit its movesheave, a rod having its one end connected to the wheel and its other end disposed through an aperture in the free end of the jaw member and having a shoulder to limit its movement through said aperture, a compression spring disposed on the rod between the free end of the jaw member and the outer end of the rod, and a nut disposed on the outer end of the rod for adjusting the amount of compression on the spring to cause the jaw member to apply a predetermined clampingeifect to the safety cable when outward movement of the arms causes the wheel to move the jaw member into engagement with the cable.

3. An elevator safety device governor comprising a frame, a shaft mounted in the frame, a

governor sheave rotatably mounted on the shaft for rotation by a safety cable, a centrifugal dement through said aperture, a compression spring r disposed on the rod between the free end of the jaw member and the outer end of the rod, and a nut disposed on the outer end of the rod for adjusting the amount of compression on the spring to cause the jaw member to apply a predetermined clamping effect to the safety cable when outward movement of the weights causes the wheel to pull the jaw member into engagement with the cable.

2. An elevator safety device governor comprise ing a frame, a governor sheave disposed in the frame for rotation by a safety cable, a pair of centrifugal armsmounted on the sheave in position to be moved outwardly by centrifugal force a plurality of teeth and rotatably mounted on said shaft concentric with the shaft and the sheave, means for biasing the ratchet wheel to a predetermined position, means associated with the centrifugal device for engaging one of the teeth on the wheel to rotate it with the sheave when the sheave exceeds a predetermined speed,

a jaw member movably mounted on the frame and having a shoe portion disposed for clamping the cable against the sheave, a stop member for limiting movement of the jaw member away from the sheave, a connector having its one end connected to the wheel and its other end disposed through an aperture in the jaw member and having means for limiting its movement through said aperture, a compression spring disposed on the connector between the jaw member and the outer end of the connector, and means for adjusting the amount of compression on the spring to cause the jaw member to apply a predetermined clamping effect to the safety cable when outward movement of the centrifugal device causes the wheel to move the jaw member into engagement with the cable.

4. An elevator safety governor comprising a frame, a shaft mounted in the frame, a sheave rotatably disposed on the shaft for rotation by a safety rope, a disk provided with a plurality of notches in its periphery and rotatably mounted on said shaft concentric with the shaft and the sheave, a centrifugal device disposed on the sheave for operation thereby, a pawl attached to the centrifugal device for engaging the notched disk and rotating it with the sheave when the sheave exceeds a predetermined speed, and means responsive to rotation of the disk with the sheave for applying a clamping action tothe safety cable.

' HAROLD V. MCCORMICK. 

